Coordinates: 60°12′N 29°42′E / 60.2°N 29.7°E / 60.2; 29.7

Location of Zelenogorsk

Gulf of Finland coast at Zelenogorsk

Former Finnish officer club, later office building of the Finnish Democratic Republic

Zelenogorsk (Russian: Зеленого́рск), Terijoki before 1948, is a municipal town in Kurortny District of the federal city of Saint Petersburg, Russia, located in part of the Karelian Isthmus on the shore of the Gulf of Finland, and a station of the Saint Petersburg-Vyborg railroad. It is located about 50 kilometers (31 mi) northwest of central Saint Petersburg. Population: 12,859 (2010 Census preliminary results); 12,074 (2002 Census).

After the Finnish War until 1917, Terijoki was part of the Grand-Duchy of Finland, ruled by the Grand Dukes of Finland, who were the Tsars of Russia, (1812–1917). Even though all of Finland was part of the Russian Empire, a customs border was in Terijoki. A valid Passport was needed for crossing the border between Russia and the Grand Duchy of Finland. Vladimir Lenin managed to travel over the border in secrecy to Finland in 1907. Later on 3 April 1917, he returned through the Terijoki border control disguised as a heater of a Finnish Railways - Finlyandsky Rail Terminal locomotive. When the Republic of Finland was established on 6 December 1917, Terijoki became a part of it, and remained so until it was occupied by the Soviet Union in the Winter War. It was regained by Finland in 1941, in the Continuation War, but then was occupied again by the Red Army and anexed to the Soviet Union again in 1944.

Terijoki was a popular summer resort since 1870, when the Riihimäki-Saint Petersburg railroad was built, and was frequented by Saint Petersburg's upper class before the Russian Revolution (1917) when the border was closed. After the Second World War its original Finnish population was displaced by people moved from Russia. At the turn of the century, the town's population was estimated to have been a few thousand, rising to above 50,000 in summer.

Terijoki became known during the Winter War as the capital of Otto Ville Kuusinen's Finnish Democratic Republic.

In the beginning of the 21st century Zelenogorsk is actively developing in all directions. Various actions for improvement of quality of life and rest in Zelenogorsk are actively carried out.

On July 25, City Day is annually celebrated; in 2009 this day has earned a fountain on a central square of Zelenogorsk park and the sculptural composition "Boots of the Traveller" on the central avenue of Zelenogorsk has been solemnly opened.

At a Dachshund monument there have been parades of dachshunds, and the museum of retrocars has shown a new exhibition.

At a concert in honor of City Day 2009 known musicians, such as Music hall theatre of St. Petersburg, Edita Piekha, and others, have played.

Cities and towns under the jurisdiction of Saint Petersburg Kolpino · Krasnoye Selo · Kronstadt · Lomonosov · Pavlovsk · Petergof · Pushkin · Sestroretsk · Zelenogorsk